What is a blocking function?

Question

What is a blocking function or a blocking call?

This is a term I see again and again when referring to Node.js or realtime processing languages.

Answer 1

var block = function _block() {
  while(true) {
    readInputs();
    compute();
    drawToScreen();
  }
}

A blocking function basically computes forever. That's what it means by blocking.

Other blocking functions would wait for IO to occur

a non-blocking IO system means a function starts an IO action, then goes idle then handles the result of the IO action when it happens.

It's basically the difference between a thread idling and sleeping.